NC fracking panel suggests wastewater could be used for irrigation

jmurawski@newsobserver.comMarch 7, 2013 

Faced with millions of gallons of potential fracking waste, North Carolina’s fracking commission could encourage drilling operators to reuse the industrial wastewater for crop irrigation.

The proposal Thursday from a member of the N.C. Mining & Energy Commission immediately raised skepticism from several environmental advocates. They said purifying brackish backwash into sprinkler water is technologically possible but in practice has caused environmental damage in other states.

Commissioner Vik Rao assured that one of the smartest options for energy companies would be to reuse the water-and-chemical mixture to hydraulically fracture numerous wells for natural gas production, then desalinate and treat the fracking fluid at the end of the cycle.

The approach would limit the volume of water used in fracking and would also solve the problem of disposal, he said. Rao chairs the Mining & Energy Commission’s Water and Waste Management Committee and said he expects his committee to create fracking standards that will encourage the reclamation of fracking fluids as a state policy.

“Treating for reuse is the cheapest thing you can do and the most environmentally safe thing you can do,” Rao said. “At the very end I would treat it (the waste) for a purpose that is easiest or most useful for a community.”

Rao is the former chief technology officer of Halliburton, the global energy conglomerate that takes credit for developing fracking technology. He recently wrote a primer on natural gas exploration.

Fracking refers to hydraulically fracturing underground rock formations with a mixture of water and chemicals to release the natural gas trapped inside. Shale gas operations now account for a third of the nation’s natural gas production.

The industrial byproduct of fracking is a mixture of water and chemicals used for extracting natural gas, as well as the brine, metals and dissolved solids that are flushed out of the ground during the fracking process. The preferred disposal method in some states is deep injection into wells for permanent storage, but North Carolina lacks suitable geology to accept potentially hundreds of millions of gallons of the toxic bilge.

The state’s natural gas is believed to be concentrated in Lee, Chatham and Moore counties. But the shale rock formations in the state’s mid-section are too impenetrable to absorb waste injections under pressure for permanent storage. Such injections would likely flow into fissures and seams, eventually mixing with fresh water, some geologists have warned.

The state’s coastal counties are the only area of the state that could potentially accept fracking waste. The coast has deep saline aquifers but it is unclear whether those aquifers are hermetically sealed off from other aquifers above, or whether injected waste would migrate over time beyond its intended resting place.

The mining commission and its committees are developing public protections and environmental safeguards to govern fracking, which is currently prohibited while the regulations are still being designed. The commission meets again Friday in Raleigh to continue its discussions.

Rao suggested that treated water could be used to water crops, or as a drinking source for sheep, which can tolerate mild salinity. His suggestions were not debated by his committee on Thursday but demonstrated the complex and controversial nature of the issue state policymakers face.

“This strikes me as a really terrible idea at first blush,” said Craig Seagall, a lawyer with the Sierra Club. “If there were purpose-built plants, such that the final discharge was clean, then I suppose there wouldn’t be a problem land-farming it, but that’s a lot of speculation.”

Reuse of treated industrial waste is done in North Carolina by food processors and other industrial operations, said Jon Risgaard, supervisor of the land application unit within the aquifer protection section of the N.C. Department of Environment and Natural Resources.

Getting a state permit requires a hydrogeologic site evaluation and groundwater modeling, and such an application could generate public opposition.

In other states natural gas drilling fluids have been treated for de-icing and dust control of roadways, as well as for land application. Though feasible, it doesn’t always work out.

Several years ago Arkansas regulators investigated 11 disposal sites and found all in violation of discharge limits of reclaimed water. Some discharged too much tainted water, others discharged water to improper sites, spreading contamination with fuel residues.

“Some fields may have been irreversibly damaged,” Arkansas authorities concluded.

Murawski: 919-829-8932

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